Attachment for lift trucks and the like



July 25, 1967 R. B. HICKMAN ET AL 3,332,715

ATTACHMENT FOR LIFT TRUCKS AND THE LIKE Filed Aug. 4, 1965 INVENTORSKENNETH H. MINDRUM RICHARD B. HICKMAN ATTORNEY United States Patent3,332,715 ATTACHMENT FOR LIFT TRUCKS AND THE LIKE Richard B. Hickman andKenneth H. Mindrum, both of Battle Creek, Mich., assignors to ClarkEquipment Company, a corporation of Michigan Filed Aug. 4, 1965, Ser.No. 477,276 9 Claims. (Cl. 294-64) This invention relates to vacuumapparatus for lifting and transporting articles of commerce,particularly paper rolls, such as heavy rolls of newsprint paper, kraftpaper, and the like.

Different constructions of vacuum apparatus for handling cylindricalarticles, particularly paper rolls, are known. Such apparatus has beengenerally found in the form of article handling attachment devices foruse with industrial lift trucks, and the present invention is concernedwith improvements in the construction of such devices.

One of the major problems encountered in the design of such attachmentdevices concerns the provision of an article engaging member capable ofadjustment to rolls of different diameters while maintaining with theroll engaged one or more sealed chambers to be evacuated so that thepaper roll or other article is held in position on the apparatus byatmospheric pressure. Generally, a plurality of articulated articleengaging pads have been utilized which are capable of pivotalself-adjustment so as to substantially conform to the curvature of rollshaving different diameters. It is a principal object of the presentinvention to provide an improved flexible article engaging means mountedin a manner to permit conformance to the curvature of rolls of differentdiameters.

Another object of the invention is to provide an improved vacuumapparatus which can effectively engage and lift a load without accuratealignment between the load and the apparatus, and which is soconstructed that it can adapt itself to a roll and the position of theroll Without accurate alignment of the roll engaging portion of thevacuum apparatus with the side of the roll.

Another object is to provide a versatile, easily controlled andrelatively low cost attachment for industrial trucks and the like, whichwill effectively adapt itself automatically to various size rolls ofpaper and similar cylindrical objects over a relatively wide range ofsizes.

Additional objects and advantages of the invention will become apparentto persions skilled in the art from the following description andaccompanying drawings, where- FIGURE 1 is a broken-away side elevationalview of an industrial truck having the present vacuum apparatus mountedon the upright thereof and showing the apparatus prepared to lift a rollof paper or other cylindrical object;

FIGURE 2 is a plan view of the article engaging portion and mountingtherefor of the vacuum apparatus in engagement with a roll of relativelylarge diameter;

FIGURE 3 is similar to FIG. 2 but shows the apparatus in engagement witha roll of relatively small diameter; and

FIGURE 4 is an enlarged fragmentary plan view of one side portion of theflexible article engaging means.

Referring now in detail to the drawings, numeral designates the forwardportion of an industrial truck having a pair of front Wheels 12, asteering mechanism 13, a tiltable upright construction 14 of knownconstruction mounted at the lower end thereof on the drive axle for thewheels 12, and a carriage mechanism 16 roller mounted on the upright 14in known manner for elevation relative thereto and on which is mountedthe apparatus 18 of the present invention.

Attachment 18 is mounted upon carriage 16 by con- 3,332,715 PatentedJuly 25, 1967 ventional brackets 20. A turntable or support plate 22 ispreferably mounted for rotation through at least by an actuatingmechanism indicated generally at 24, located intermediate support plate22 and a plate 26 to which brackets 20 are secured. An upper vacuumreserve tank 28 is mounted upon and extends transversely of plate 26 andan upper plate 30. A lower vacuum reserve tank 32 is secured to plate26. A suitable mechanism for rotating plate 22 is described and claimedin Patent No. 3,198,023, issued Aug. 3, 1965. It consists generally of apair of hydraulic cylinders 34 and 36, each having a piston therein witha rack on the inner edge for engaging the teeth on a pinion, not shown,so that movement of the pistons in opposite directions in one senserotates the pinion which is rigidly secured to plate 22 by a ring ofbolts, and thus rotates the plate to various angular positions asrequired for rotational positioning of the paper roll 40. The cylindersare mounted in a cover plate 42 adjacent each of the cylinder ends,which are secured to transverse backing plates 44 and 46, which in turnare secured to base plate 26. A vacuum conduit, not shown, extendsthrough an axial opening in the rotator assembly 24 and is connected toa conduit 48 of a vacuum filter assembly 50 mounted upon the front sideof support plate 22, and a conduit 52 is connected to the filter 50 andto a central opening 53 formed in a flexible load engaging base platemember 54 of this invention. A vacuum pump and controls therefor, notshown, are adapted to evacuate reservoirs 28 and 32 and a chamber formedbetween the surface of roll 40 and roll engaging member 54, in a mannerto be explained, Whenever a roll 40, or the like, is in sealing relationwith member 54.

The structure described above, except load engaging member 54, is knownand does not form a necessary part of the present invention, and so hasbeen described in general background terms which will sufiice for thepresent purpose. It will be understood, for example, that it is notnecessary to the practice of the present invention to utilize it witheither the truck 10 or with rotating mechanism such as is describedgenerally above. The present invention, as best shown in FIGS. 24, maybe utilized with any means for supporting the same, such as exemplifiedby the lift truck shown in FIG. 1, and with a source of vacuum capableof evacuating the chamber formed as aforesaid when the member 54 engagesa roll for moving the latter from one location to another. Although useof our invention in conjunction with a lift truck may best exemplify itsutility, it is not intended that the invention be so limited.

Extending outwardly of support plate 22 on each side thereof are pairsof transversely spaced upper and lower support brackets 60 and 62 eachof which is connected at the outer end thereof to a pair of pivotedlinks 64 mounted above and below each bracket 60 by pins 66.

vSecured to member 54 in vertically spaced relation adjacent each sideedge thereof is a pair of bracket members 68 to which the opposite endsof links 64 are pivoted by pins 70 so that when the member 54 is mountedfrom plate 22, each pair of brackets which is connected by a link 64 islocated in a substantially horizontal plane. In addition, upper andlower pairs of facing support brackets 72 and 74 are secured to thefront side of plate 22 and the rear side of member 54 in the centersection thereof, which pairs of adjacent brackets are connected togetherby means of a four-bar or parallelogram linkage 76, one corner portionof which is pivotally mounted upon .one of the brackets 72 and theopposed corner portion of which is pivotally mounted upon the adjacentbracket 74.

Load engaging member 54 comprises a curved platelike, semi-rigidflexible member, which may be constructed, for instance, of a reinforcedrubber-like material, such as rubber reinforced with cord or fabric 'as,for

example, in the side wall construction of automotive tires. An importantfactor is that the material be sufficiently rigid to avoid collapsingunder capacity loads for which it is designed to carry, and yet besufliciently flexible so that it may flex a substantial amount in thedirection of the curvature of the roll to be engaged thereby; i.e.,substantially rigid in the direction transverse to the curvaturethereof, and relatively flexible in the direction of the curvature ofthe member.

In order to rigidify the member 54 in a direction transverse to thecurvature thereof, we have provided T-section metal beams 78 embeddedwithin an enlarged portion '80 at each side of member 54. The brackets68 extend into slots formed within each enlarged portion 80 and aresecured, as by welding, to the beams 78. The member 54 is preferablyprestressed so that the curvature thereof comprises a segment of acircle which is substantially less than a semi circle when the member isflexed into a position of maximum curvature for handling the smallestdiameter roll within the range of rolls which the device is designed tohandle. An outwardly extending flexible sealing lip or edge 82 is formedintegral with member 54 and extends around the entire periphery thereofso that when a roll is engaged a seal is formed with the surface of theroll; a corrugated section 84 is formed on the inside curved surface ofmember 54 and extends around the periphery thereof adjacent sealing lip82. The purpose of the corrugated section 84 is to insure that uponengagement with a roll a closed and sealed chamber will be formedbetween the adjacent curved surfaces of the member 54 and the rollhaving a depth equal to or somewhat less than the chamber depth shown inFIG. 4 at numeral 86, thereby insuring that the adjacent surfaces of theroll and member 54 will not be in contact which would inhibit theapplication of full vacuum to support the roll thus engaged. In otherwords, corrugated section 84 insures themaintenance of an adequate depthof the chamber to be evacuated so that when the operator actuates avacuum control valve to communicate opening 53 with the vacuum pump andreservoirs 28 and 32, chamber '86 will be substantially instantaneouslyevacuated, and the roll engaged with full vacuum pressure.

It will be noted in FIG. 2 that a roll of relatively large diameter isengaged by member 54, and in FIG. 3 a roll of relatively small diameteris thus engaged. The member 54 is preferably prestressed so that in anunflexed condition the member 54 has a curvature slightly greater than,or a radius slightly less than, that of the smallest diameter roll whichit is designed to engage. When the lift truck of FIG. 1, for example,moves the article engaging attachment into position to handle a smalldiameter roll, such as shown in FIG. 3, member 54 is flexed a slightamount outwardly upon the application of force between member 54 and theroll so that the curvature of member =54 conforms to that of the rolland a sealing relation is established between the surface of the rolland the inner peripheral surface of lip 82, whereupon the application ofvacuum to the sealed chamber formed between the roll and member 54effects the instantaneous engagement of the roll for lifting andtransporting it. In the assumed condition of handling a roll of smalldiameter the parallelogram linkage '76 is flexed slightly so that thecorner portions thereof connected to brackets 72 and 74 move somewhatfurther apart as the opposite corner portions move slightly together andthe outer ends of links 64 move outwardly during the movement of member'54 into conforming surface engagement with the roll.

In *FIG. 2 a roll of relatively large diameter is shown engaged by ourdevice, which has been actuated with some force into the side surface ofthe roll so that member 54 is flexed to conform to the curvature of thelarger roll diameter, at which point lip 82 forms a seal with the rolland the opposed corner portions of parallelogram linkages 76 areactuated further in the directions previously noted and assume aposition as illustrated in FIG. 2,

with pairs of links 64 pivoting further outwardly, as shown. Theapplication of vacuum pressure to the abovementioned chamber formedbetween the roll and member 54 secures the larger roll to the device inthe same manner as described above with respect to FIG. 3.

During all load handling operations, it will be noted that T-sectionbeams 78 rigidify member 54 in the direction indicated so that it isrelatively inflexible in a direction transverse to the curvaturethereof, which is desirable. To disengage the roll a control valve, notshown, is opened to permit the pressure in the aforementioned chamber toincrease to atmospheric pressure, whereupon the load is released.

From the foregoing it will be appreciated that our device provides animproved means of engaging various sizes of cylindrical objects, such asrolls of paper, with a single semi-rigid flexible gripper pad inaccordance with our invention, and that the means for mounting thegripper pad on support plate 22 enables it to conform to rolls whichvary considerably in diameter.

While the present device has "been illustrated primarily in connectionwith paper rolls, it may be used equally satisfactorily in handling anycylindrical objects of substantially the same size and shape as paperrolls. Further, although we have described and illustrated only oneembodiment of our invention, it will be apparent to those skilled in theart that various changes in the structure and relative arrangement ofparts may be made without departing from the scope of our invention.

We claim: v

1. A vacuum actuated roll handling device comprising load engagingflexing base plate means prestressed to provide a curvature in onedirection having a predetermined radius smaller than the radius of thelargest roll to be engaged and adaptable to increase its radius byflexing under external force imposed by engagement with a roll, a

rigid elongated member embedded in each side portion of the base plateand extending in a direction generally transverse of the curvaturethereof, said base plate having a sealing lip for providing a vacuumseal with the surface of a roll engaged thereby which forms a chamberwith the surface of the base plate, means supporting the base plate insuch a manner that it is conformable as aforesaid to the curvature ofdifferent size rolls, and means for evacuating said chamber so that aroll may be supported by said flexing base plate.

2. A device as claimed in claim 1 wherein the sealing lip extendsperipherally of said chamber, and said mounting means includes bracketssecured to said rigidifying means.

3. A vacuum actuated roll handling device comprising a rigid supportmember, a flexible curved plate means spaced from said support member,mounting means connected to said support member and to said plate meansindependently at opposite side portions of the plate means and alsocentrally thereof, at least a portion of said mounting means beingmovable in both longitudinal and pivotal directions in relation to saidsupport member during flexure of said plate means, said plate meanshaving a curved configuration adjustable by an external force imposed onthe plate means directly by a roll to be engaged from a curve ofrelatively small radius to one of larger radius, said plate means beingadapted to engage in sealing relationship rolls of different diametersand forming therewith a sealed chamber, and means for evacuating saidchamber for engaging the roll.

4. A device as claimed in claim 3 wherein rigid means extendstransversely of the curvature of the plate means and integral therewithfor preventing excessive flexure of the plate means in a directiontransverse of the curvature thereof.

5. A vacuum actuated roll handling device comprising curved loadengaging flexing base plate means having an adjustable curvature in onedirection, means rigidfying opposite side portions of the flexing baseplate, said rigidifying means comprising rigid elongated membersembedded in each side portion of the base plate and extending in adirection generally transverse of the direction of curvature thereof,mounting means for the flexing base plate supporting the base plate forflexure such that the base plate is conformable to the curvature ofrolls of different diameters engageable thereby, an endless sealing lipsecured to and extending around a face of the base plate to provide avacuum seal between the surface of a roll engaged and the surface of thebase plate, and means for evacuating the chamber formed between saidlatter surfaces.

6. A device as claimed in claim 5 wherein said mounting means includesparallelogram linkage means connected at opposed corner portions thereofto the flexing base plate and to a mounting plate for extension andretraction with varying curvature flexure of the base plate.

7. A vacuum actuated roll handling device comprising load engagingflexing base plate means prestressed to provide a curvature in onedirection having a predetermined radius smaller than the radius of thelargest roll to be engaged and adaptable to increase its radius byflexing under external force imposed by engagement with a roll, meansrigidifying opposed side portions of the flexing base plate in adirection generally transverse of the curvature thereof, said base platehaving a'sealing lip for providing a vacuum seal with the surface of aroll engaged thereby which forms a chamber with the surface of the baseplate, means supporting the base plate in such a manner that it isconformable as aforesaid to the curvature of diflierent size rolls, saidsupporting means including parallelogram linkage means connected atopposed corner portions thereof to the base plate and to a mountingplate for extension and retraction with flexure of the base plate, andmeans for evacuating said chamber so that a roll may be supported bysaid flexing base plate.

8. A vacuum actuated roll handling device comprising a rigid supportmember, a flexible curved plate means spaced from said support member,mounting means connected to said support member and to said plate meansat opposite side portions of the plate means and also centrally thereof,said plate means having a curved configuration adjustable by an externalforce imposed on the plate means directly by a roll to be engaged from acurve of relatively small radius to one of larger radius, said mountingmeans including parallelogram linkage means connected at opposed cornerportions thereof to the plate means and to said rigid support member forextension and retraction with varying curvature flexure of the platemeans, said plate means being adapted to engage in sealing relationshiprolls of different diameters and forming therewith a sealed chamber, andmeans for evacuating said chamber for engaging the roll.

9. A vacuum actuated roll handling device comprising a rigid supportmember, a flexible curved plate means spaced from said support member,mounting means connected to said support member and to said plate meansat opposite side portions of the plate means and also centrally thereof,said mounting means being movable during flexure of said plate means, arigid elongated member embedded in each side portion of the plate meansand extending in a direction generally transverse of the direction ofcurvature of the plate means, said mounting means being connected tosaid member at opposite side portions of the plate means, said platemeans having a curved configuration adjustable by an external forceimposed on the plate means directly by a roll to be engaged from a curveof relatively small radius to one of larger radius, said plate meansbeing adapted to engage in sealing relationship rolls of dilferentdiameters and forming therewith a sealed chamber, and means forevacuating said chamber for engaging the roll.

References Cited UNITED STATES PATENTS 3,227,481 1/ 1966 Creskoff 294-643,227,482 1/1966 Harris 29464 3,257,141 6/1966 Buus 294-655 3,260,3917/1966 Horton 29465.5 X 3,276,611 10/1966 Horton 214650 GERALD M.FORLENZA, Primary Examiner.

G. ABRAHAM, Assistant Examiner,

1. A VACUUM ACTUATED ROLL HANDLING DEVICE COMPRISING LOAD ENGAGINGFLEXING BASE PLATE MEANS PRESTRESSED TO PROVIDE A CURVATURE IN ONEDIRECTION HAVING A PREDETERMINED RADIUS SMALLER THAN THE RADIUS OF THELARGEST ROLL TO BE ENGAGED AND ADAPTABLE TO INCREASE ITS RADIUS BYFLEXING UNDER EXTERNAL FORCE IMPOSED BY ENGAGEMENT WITH A ROLL, A RIGIDELONGATED MEMBER EMBEDDED IN EACH SIDE PORTION OF THE BASE PLATE ANDEXTENDING IN A DIRECTION GENERALLY TRANSVERSE OF THE CURVATURE THEREOF,SAID BASE PLATE HAVING A SEALING LIP FOR PROVIDING A VACUUM SEAL WITHTHE SURFACE OF A ROLL ENGAGED THEREBY WHICH FORMS A CHAMBER WITH THESURFACE OF THE BASE PLATE, MEANS SUPPORTING THE BASE PLATE IN SUCH AMANNER THAT IT IS CONFORMABLE AS AFORESAID TO THE CURVATURE OF DIFFERENTSIZE ROLLS, AND MEANS FOR EVACUATING SAID CHAMBER SO THAT A ROLL MAY BESUPPORTED BY SAID FLEXING BASE PLATE.